1. Field of the Invention
The present invention relates to a transport device for separately transporting, one by one, small electronic parts, such as chip-type capacitors and to an inspection apparatus using the transport device.
2. Description of the Related Art
In recent years, there is an increase in the number of requests for characteristic-discriminating apparatuses for electronic parts. The characteristic-discriminating apparatus is needed to inspect various characteristics by a single apparatus. In order to meet such a request, Japanese Unexamined Patent Application Publication No. 2-195272 proposes a characteristic measuring apparatus which includes a movable table with a plurality of retaining holes for passing and holding electronic parts so that both ends of the electronic parts protrude therefrom. A plurality of fixed terminals are arranged in a plane corresponding to the retaining holes of the movable table. A plurality of movable terminals are placed opposed to the fixed terminals with the movable table therebetween.
Characteristic-discriminating apparatuses are also requested to improve throughput. For some recently improved electronic parts such as chip-type capacitors, however, the capacitance has been increased, and the measuring time (time for measuring insulation resistance) tends to be longer than prior capacitors. When characteristic discrimination is performed for these electronic parts, which need a long measuring time, if only one line of retaining holes is formed in the movable table, as described above, the number of electronic parts that can be processed in a certain time is limited, and an improvement of throughput cannot be expected.
As a means for improving throughput, Japanese Unexamined Patent Application Publication No. 11-292252 proposes an apparatus in which a rotary disk has a plurality of concentric lines of cavities. After electronic parts are introduced into the cavities, they are conveyed to a transfer section and are then transferred to a holding plate or the like. By applying this rotary disk having a plurality of cavities to a characteristic-discriminating apparatus, throughput can be improved.
In order to further improve throughput, however, it is important to know how many working areas can be provided between the area where the electronic parts are introduced into the rotary disk until the area where they are removed. That is, it is important to know to what extent an area excluding the functional blocks, can be enlarged. The functional blocks are defined as essential for the characteristic-discriminating apparatus, such as the electronic part supply and removal sections. In the transfer apparatus described in Japanese Unexamined Patent Application Publication No. 11-292252, a large accommodating section having a comb-shaped guide is disposed in an electronic part delivery section. The electronic parts are introduced into the accommodating section at random, are aligned by the comb-shaped guide and are supplied to the cavities of the rotary disk. Therefore, the receiving section occupies a large space equivalent to about 25% of the entire rotary disk. This limits the working area necessary for characteristic discrimination.
Accordingly, it is an object of the present invention to provide a high-throughput electronic part transport device in which the space of a receiving section is reduced so that a working area is enlarged, and an inspection apparatus using the transport device.
In order to achieve the above object, according to an aspect of the present invention, there is provided an electronic part transport device including a) a transport medium having a plurality of lines of cavities, the lines being concentric with respect to a rotation axis, b) a driving means for rotationally driving the transport medium, c) a supply means for separating and supplying a plurality of randomly introduced electronic parts one by one, d) a delivery means for feeding the electronic parts separately supplied by the supply means into the cavities of the transport medium, and e) a removal means for removing the electronic parts from the cavities of the transport medium.
When electronic parts are introduced into the supply means at random, they are separated one by one and transported by the supply means, and are fed into the cavities of the transport medium by the delivery means. In order to improve throughput, the transport medium is provided with a plurality of cavities which are arranged in lines concentric with respect to the rotation axis. By conveying a plurality of electronic parts held in the cavities, the transport efficiency can be multiplied by the number of cavity lines. When the electronic parts are conveyed to a predetermined position by the transport medium, they are taken out of the cavities by the removal means.
Since the electronic parts are thus separated one by one before being inserted into the cavities of the transport medium, it is only necessary for the delivery means to simply insert the electronic parts into the cavities. For this reason, delivery errors are prevented, the receiving section does not occupy a large space, and a working area can be provided on the transport medium.
Preferably, the supply means includes a) a parts feeder having the same number of aligning paths as the number of cavity lines of the transport medium so as to successively supply the randomly introduced electronic parts while aligning the electronic parts in the aligning paths, and b) a separating means disposed at the distal end of each of the aligning paths so as to separate one by one the electronic parts successively conveyed by the parts feeder.
The parts feeder is formed of, for example, a combination of a bowl feeder and a linear feeder. The same number of parts feeders as the number of the cavity lines of the transport medium may be arranged. The separating means may be disposed at the distal end of each of the parts feeders. Alternatively, the same number of linear feeders (aligning paths) as the number of cavity lines of the transport medium may be connected to a single bowl feeder. The separating means may be disposed at the distal end of each of the linear feeders. By providing a stopping means for temporarily stopping the movement of the second part of the parts conveyed in an aligned state, only the leading part can be easily separated.
Preferably, the supply means includes a) a parts feeder for successively supplying a plurality of electronic parts introduced at random while aligning the electronic parts, b) a distributing rotor for distributing the electronic parts aligned and supplied by the parts feeder into a plurality of recesses formed on the outer periphery thereof, and c) a driving means for rotationally driving the distributing rotor in one direction.
In this case, the electronic parts aligned by the parts feeder are individually held in the recesses of the distributing rotor, and are thereby separated one by one. By simultaneously feeding the same number of electronic components, of the electronic parts held in the recesses of the distributing rotor, as the number of cavity lines of the transport medium by the delivery means, an efficient reception is possible. Since a single parts feeder will do in this case, the entire device can be decreased in size, and the cost can be reduced.
Preferably, the supply means includes a) a feeding disk having on its upper surface a feeding groove extending in the radial direction so as to align the electronic parts, b) a recess disposed at the outer peripheral end of the feeding groove so as to hold one electronic part, the upper surface being inclined with respect to the horizontal plane, and c) a driving means for rotationally driving the feeding disk in one direction. A plurality of electronic parts randomly introduced on the upper surface of the feeding disk are guided from the feeding groove to the recess by rotating the feeding disk, and are separately held in the recess and removed therefrom. Such a feeding disk is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 11-208871. When multiple electronic parts are introduced on the feeding disk at random, they are collected at the bottom due to the inclination of the upper surface of the feeding disk. Some of the electronic parts fall into the feeding groove due to the rotation of the feeding disk, and are oriented in a predetermined direction. Since the feeding groove is continuously formed in the radial direction on the upper surface of the feeding disk, the probability that the electronic parts will fall into the feeding groove is increased. The electronic parts which fall into the feeding groove slide to the outer peripheral end of the feeding groove due to gravity, and enter the cavities. When the feeding groove is turned upward, the electronic parts therein slide downward (toward the center) due to gravity, and only the electronic parts held in the cavities remain. In this way, the electronic parts are separated one by one.
In this case, since the feeding disk serves as both the parts feeder and the separating mechanism, the size and cost of the device are further reduced. Moreover, since there is no need to provide a vibration source such as provided in the parts feeder, quietness is ensured. Thus, there is little adverse effect due to noise during the characteristic measurement.
Preferably, the delivery means is a transfer chute having a plurality of guide paths for separately guiding the electronic parts separately supplied by the supply means to the respective lines of cavities of the transport medium.
When a discharge section of the supply means is circular, since the cavities of the transport medium are arranged in an arc form, when a plurality of electronic parts are simultaneously fed into the cavities, they are prone to fall off therebetween. Accordingly, by respectively guiding the electronic parts separately supplied by the supply means into the cavities in the lines of the transport medium by using the transfer chute having a plurality of guide paths, the electronic parts can be prevented from falling off or from being delayed, and can be reliably fed into the cavities.
The electronic parts can be more reliably fed into the cavities of the transport medium using an air suction device or an air blowing device.
Preferably, an inspection apparatus is constructed by providing a plurality of inspecting sections around the transport medium so as to simultaneously inspect the same number of electronic parts held in the cavities as the number of lines of cavities.
In this case, the same number of electronic parts as the number of the cavity lines can be simultaneously processed, and this easily speeds up the processing. By reducing the receiving space where the electronic parts are fed into the transport medium, the inspection area on the transport medium can be maximized.
In this case, the inspection sections serve to perform, for example, visual inspection or electrical characteristic measurement.
Preferably, the inspecting sections are each formed of a characteristic measuring device having a measuring terminal. The electrical characteristics of the electronic parts held in the lines of cavities are measured by contacting the measuring terminals with the electronic parts when the transport medium is rotated to a predetermined position.
It is preferable that the measuring terminals are contacted simultaneously with the electronic parts held in the cavities in the lines. For example, when the transport medium has four concentric lines of cavities, by taking a characteristic measurement with measuring terminals contacted simultaneously with four electronic parts, the measuring time per electronic part can be increased to four times the conventional measuring time (when one line of cavities are provided). This makes it possible to achieve an inspection apparatus suitable for insulation resistance measurement for capacitors or the like which needs a long measuring time.
Further objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.